Ask HN: What's the point of mandatory schooling?

To make sure everyone is on the same page, I'm talking about mandatory schooling from grades 6 through 12 in the United States. I'm also talking about an average school you'll find everywhere in the US, not the special schools they talk about in talks like TED. For several years in my life, I've been wondering, what was the point of school? Various people throughout my life said that school was for learning. The interesting thing was, I learned 100x more on my own than from school. In fact, a lot of things school taught me was wrong, very very wrong and it took me several years to unlearn it. The worst areas were in history where almost everything I learned was a complete lie. People also said, don't worry about the education but school should be for socializing. While true in a way, that isn't the whole story. Right now, looking back, the vast majority of kids I went with aren't doing that great. In fact, the most successful ones are the ones who socialized the least in school. If I did socialize with these kids, yes I would have more socializing skills but they would be with people who are A) working at extremely low paying jobs, B) doing massive amounts of drugs and alcohol, C) have kids that they are trying to take of with those low paying jobs, or D) stranded in the military trying to figure out a way to succeed (so far, those guys still haven't made it out). I mean, yes, there are some that came out and are doing great but those are a small minority of my graduating class. I learned way more from socializing with grown adults and elderly than I did from school socialization. Most my education was self-reading and then finding and talking to adults in the field asking them questions about it while at school, the teachers were trying to continually teach me wrong stuff - and give me an F if I didn't agree with them! Some say school is for jobs and well, these adults I learned to socialize with as a kid are more than willing to offer me jobs. So which comes to my question. Early schooling was useful. It taught me how to read and write. But after that, what was the point of mandatory schooling? Why does everyone I know say school is so important even though I don't see that great results coming from the other end of the system? More importantly, why does everyone I see seem to miss it. Especially those in the lowest paying & horrible jobs out there. From my end, it seems like I wasted (and still wasting trying to unlearn "wrong" material) several years of my life in school. P.S. Again, the school I'm talking about is the average common school found in the US. Not those special schools you hear about in TED talks.